The present invention relates to a combination lock which is unlocked by turning the numeral discs to a present combination of numbers.
Combination locks of the above feature are very popular because the user only has to remember a combination of numbers for unlocking the lock, and does not have to carry a key, thereby avoiding the risk of losing the key.
Referring to FIG. 9, a conventional combination lock has a male member 10 and a female member 20. The male member 10 has a toothed rod 101 having engaging teeth 102 spaced apart on an upper side. The female member 20 has a receiving tube 201, several numeral discs 202 and locating washers 203.
The receiving tube 201 has a slot on an upper side for permitting the engaging teeth 102 to be passed through when the engaging teeth 102 to be passed through when the toothed rod 101 of the male member 10 is inserted into the female member 20.
The numeral discs 202 are each connected to a corresponding one of the locating washers 203. The numeral discs 202 are turnably passed through the receiving tube 201, and each has an unlocking number corresponding to a gap formed on an inner side of the numeral disc 202. A C-shaped ring 204 is fitted to the fixing trench 205 to confine the numeral discs 202.
The numeral discs 202 have to be turned to an unlocking position according to the unlocking numbers, forming a passage above the slot of he receiving tube 201 for the engaging teeth 102 to disengage from the numeral discs 202. Thus, the male member 10 can be separated from the female member 20 to unlock the combination lock.
The male member of the conventional lock usually connects a cable for use on a bicycle. However, the conventional lock is found to have a very limited use, unable to be used with a steering wheel lock of a car which has a long and thick locking rod or with a motorcycle lock having an U-shaped locking rod. Consequently, steering wheel locks and motorcycle lock still have to be used with conventional keys, unable to provide users with the convenience of keyless unlocking.
Therefore, it is a main object of the present invention to provide a keyless combination lock which has wide variety of uses.
The combination lock of the present invention includes
a lock main body having several turnable numeral discs; the numeral discs can be turned to an unlocking position according to the preset combination of unlocking numbers;
a toothed rod passed into the lock main body; the toothed rod has engaging teeth on an upper side separably engaging the numeral discs such that the toothed rod is movable when the main body is in the unlocking position; the toothed rod has a separating wall on an outer end and a protruding plate on the wall;
a housing part fixed receiving the lock main body; the housing part has a second through hole perpendicular to the toothed rod;
an engaging rod passed into the second through hole; the engaging rod has a front engaging end and an intermediate recessed portion; the engaging rod is biased forwards by a spring to engage a toothed locking rod passed through the housing part from the engaging end;
a turnable rod passed through the lock main body and the housing part with a lower semi-circular pushing block disposed on the engaging rod recessed part; the turnable rod has an intermediate portion having a flat side; the flat side abuts the protruding plate of the toothed rod when the lock is in the locked position, preventing the turnable rod from turning; the pushing block pushes the engaging rod rearwards for the engaging end to disengage from the toothed locking rod when the lock is unlocked and the turnable rod turns.
The locking rod can be made into various shapes for different purposes, including an elongated one suitable for a steering wheel lock, and an U-shaped one suitable for a motorcycle lock.